0:13Skip to 0 minutes and 13 secondsMy colleague, Steve Bernie, and I will take you through the next few weeks. Steve graduated with a PhD in mechatronic engineering. My background is in material science. I think you'll see how the effective integration of those skills and others is critical to the further development of 3D bioprinting. So what is 3D bioprinting? Well, 3D bioprinting involves the assembly of structures for medical applications. In 3D bioprinting, we can create structures that are either wearable or implantable. We can create structures of a single material or of multiple materials. There's been so much progress in recent years due to a collision of advances in material science, mechatronic engineering, cellular biology, tissue engineering, and also the ability to integrate all of those skills together.

1:07Skip to 1 minute and 7 secondsBut there's no doubt that 3D bioprinting has built on the foundations of more traditional 3D printing. And, Steve, I guess you can tell us that 3D printing has been around for quite some time. That's right, Gordon. 3D printing has been around for over 30 years. It would have started off with the production of simple components, allowing people to prototype devices in a very simple manner or means. Over the years, it's expanded with a range of materials and also the technologies that are used to allow us to develop greater detailed components with a greater range of material and material properties. As the technology has moved on and expanded though, we've got a much greater range of materials.

1:42Skip to 1 minute and 42 secondsWe've also dramatically increased the resolution. Where previously, our quality of layer resolution would have been about a quarter of a millimetre, we've now got layer resolutions down as fine as 16 microns. And in the case of this component, we've got layer resolution of 30 microns with two materials being printed simultaneous into the same component, giving you a component that's impossible to manufacture by conventions means. And so what is it about 3D printing that makes the creation of a structure like that possible? Well, it's the fact that 3D printing is so flexible. The hardware itself doesn't change. It's the design of the component that you're producing that changes.

2:18Skip to 2 minutes and 18 secondsSo in your software, you can develop a component or a structure, decide where to deposit materials in a two-dimensional slice, and then stack those slices together to give you a three-dimensional structure. So it's that flexibility of design that's the real differentiator. And so the excitement and the beauty of 3D printing is in its simplicity, the ability to build things up, layer by layer. That's exactly right. So layer by layer production, anything that you can visualise in a three-dimensional space or have in a computer environment, generally, we can reproduce in a 3D printer. These are great examples based on polymers, but also metal printing in three dimensions? Absolutely. So it's a more immature technology.

2:55Skip to 2 minutes and 55 secondsIt would have originated in the last 15 years. But with this technology, we're able to make fully dense components of highly complex geometries that truly are impossible to manufacture by any other means and produce real high-quality results. So you can see, this is a personalised hip implant, or a scaled version of a personalised hip implant. The fixation points themselves have been captured from CT or MRI data, and then incorporated into the base design of the component. That unique component is then manufactured on a selective laser melting system, taken from the system, cleaned, polished, and prepared for implantation. We can also start to look at very functional structures that provide structural support but also provide some bioactivity.

3:38Skip to 3 minutes and 38 secondsAnd that's even true, Stephen, of these hollow screws here that came about through an idea from one of the orthopaedic surgeons that we work with. The simple feature of putting a hole through the centre of it and then post-loading that with a drug is something that hadn't been thought of before. And it's very easy for us to develop that through a 3D printing technology. So there are drugs, as Steve mentioned, which might fight against inflammation once a 3D part has been implanted. There are also the ability to put particular proteins into those structures that might facilitate a particular type of tissue to grow around that structural implant and therefore, improve its performance.

4:16Skip to 4 minutes and 16 secondsAnd then of course, we start to think about not only structural support, but high-level bioactivity. So can we create structures which are going to be compatible with living cells? Now that's going to require the ability to print much softer materials, what we would call gel-like materials. And they're called gel-like because they're basically like jelly and have a very high water content. Now of course, that makes them immediately applicable and immediately integratable with biological systems. So printing softer materials like this has really developed very rapidly in recent years, hasn't it, Steve? That's right. Absolutely. And where we're able to take the fundamental hardware-- so extrusion, inkjet, and laser centering processes-- and apply those to these more bioactive materials, biorelevant materials.

5:05Skip to 5 minutes and 5 secondsIn the end, of course, the ultimate goal in bioprinting or for particular applications is to integrate the patient's own cells, stem cells, throughout these soft structures. So to do that really requires us to go back and think about, how do we create bio-inks? So imagine there's a bio-ink that can sustain and support living cells in an ink reservoir before printing. And then a bio-ink which also contains other materials to protect that cell, protect that cell during the printing process. And then to allow it to form into three-dimensional structures on the other side of the inkjet head.

5:44Skip to 5 minutes and 44 secondsSo the whole idea of 3D bioprinting relies on advances in materials, advances in our understanding of how those materials interact with living cells, how we can create the inks that are appropriate to the delivery machinery that's brought about through advances in mechatronic engineering. Without advances in any one of those steps, we can't realise the true potential of 3D bioprinting.

What is 3D bioprinting?

You will appreciate that as we describe 3D bioprinting to you and how it can solve real clinical issues, that there is another need and that is the need for appropriately trained personnel.

This is a multi-discipline area of activity. Scientists need to be able to communicate with engineers, who must communicate with cell biologists, who must communicate with clinicians. It is only through that effective integration of all those skills that we will realise the true potential of 3D bioprinting in the clinical setting.